AMD ATI Radeon HD 5970 Video Card Review

Just when you thought there was no way to outdo the 5800 series, AMD gives us the ATI Radeon HD 5970. It has two GPUs on a single PCB and brings with it CrossFireX in a single PCIe x16 slot. We show you if it is worth your hard earned cash.

Introduction

Can you hear that? It is the sound of another AMD GPU launch! AMD’s GPU product codenamed "Hemlock" is here!

We’ve now have a total of five new AMD GPU models scaling from the very expensive high-end down to the inexpensive low-end. All launched since September 22 of this year.

The new ATI Radeon HD 5970 is being launched today. The 5970 is AMD’s answer to the very high-end, culminating in a dual-GPU on a single PCB video card. Think of it as two Radeon HD 5870s (down-clocked) and put into a single video card package.

You are probably tired of this slide by now, but it has been updated to now include the new Radeon HD 5970 (codename Hemlock) video card. This now takes us all the way from the Radeon HD 5750, to the Radeon HD 5770, to the Radeon HD 5850 to the Radeon HD 5870 to the now Radeon HD 5970.

What’s in a Name?

Why was the Radeon HD 5970 not named "5870 X2" suggested by previous naming schemes? The answer is actually quite simple, and is in two parts. First, the Radeon HD 5970 does not use the same ASIC as the Radeon HD 5870, so it is not technically a "5870 X2." Or at least that is what we were told, but as of writing this, we are not sure what that difference is. The other reason is because it isn’t exactly twice the performance of the Radeon HD 5870 either, and AMD smartly decided to differentiate the product name here. (Some jackass somewhere probably sued them over that last time!)

Specifications

The first specification we need to talk about is the price; you might want to sit down for this one. The Radeon HD 5970 has a set MSRP of a whopping $599. This is certainly not a mainstream video card at this price. But what does that buy you?

It buys you two 1600 stream processor GPUs on a single PCB. The Radeon HD 5970 shares all the same internal specifications (on each GPU) to the Radeon HD 5870, save for clock speed differences. You will find the familiar 1600 stream processors per GPU, 32 ROPs, and 80 texture units per GPU. You will also find the familiar 256-bit memory bus and 1GB framebuffer per GPU configuration.

The differences are in the clock speeds. Both GPUs will run at 725MHz and the memory will run at 4GHz. The Radeon HD 5870, for comparison, runs at 850MHz GPU and 4.8GHz memory. The reason for these clock speed differences is quite simple. AMD’s design goal with the Radeon HD 5970 was make it perform within a 300 Watt power envelope. In order to do so, these are the clock speeds it must be at stock. Fear not however, AMD thought of us enthusiasts too.

Dual-GPU Enthusiast Video Card?

Yes, though AMD designed this video card to operate in a 300W power envelope stock, they gave it room to expand to a 400W envelope by manual tweaking! This is where it gets fun.

AMD has gone to great lengths to design this video card with room to grow. AMD is cherry picking each Radeon HD 5970 GPU to ensure the best potential for overclocking. (Conversely this means that other 5870 GPUs might suffer from "lesser" OCing down the line we would have to assume.) Along with that, they are choosing to use the best components and high-grade material for the Radeon HD 5970. AMD is using digital programmable voltage regulators, pure ceramic super-capacitors and have also included actual circuitry for real-time power monitoring.

The stock cooling system has been designed to accommodate 400W of heat produced by this video card. Since the Radeon HD 5970 operates in a 300W power envelope stock, the cooling system is not burdened at stock frequencies and voltages. AMD have actually designed the cooling system with headroom for voltage increases and clock frequency increases.

AMD has also unlocked Overdrive in Catalyst Control Center; you will be able to set the GPU frequency up to 1GHz for both GPUs. You will be able to set the memory up to 6GHz. The options are in the sliders at least, but no guarantee you can achieve that. AMD is also providing an over-voltage utility to add-in-board partners, with which they can design their own programs to gain control over voltage tweaking on the Radeon HD 5970. This means we should see many more utilities from AIBs to control voltage and clock tweaking. Since there is now circuitry for hardware monitoring we will also see these applications provide real-time statistics for the video cards health.

With all of these features there is no questioning that this video card is geared for enthusiasts like us, and contains a lot of potential for higher clock speeds.

Eyefinity

The Radeon HD 5970 fully supports triple display (up to 2560x1600 each) Eyefinity configurations. That is, you may run triple displays in Eyefinity and experience your games across three displays fully accelerated by both GPUs. This has been supported in the latest driver we are using and this driver will be available to the public on launch day. However, ONLY the Radeon HD 5970 is supported for dual-GPU Eyefinity acceleration currently. You cannot run HD 5870 CrossFire or 5850 CrossFire and experience dual-GPU acceleration in Eyefinity for now, although we are promised this will be to us soon.

The reason why the Radeon HD 5970 supports Eyefinity now is because it was easier to get working first. The onboard PLX PCIe chip on the video card gives AMD a known set of PCI Express lanes to work with, and knowing that the configuration will never change they were able to get Eyefinity working with this configuration first. A future driver down the road (not Catalyst 9.12, so think 2010 for support) will enable CrossFire on Eyefinity for all other configurations.

The reason it is taking so long is because of the unknown configurations CrossFire will be used in with Eyefinity. AMD must account for all known combinations, and it takes a lot longer to validate games in CrossFire in an Eyefinity configuration. In fact, the Radeon HD 5970 will have a white list of games that are validated and working in Eyefinity with dual-GPU acceleration. We will post that list when it is online. Therefore, if you require the power of dual-GPU 3D acceleration in an Eyefinity configuration, your only choice is the Radeon HD 5970 for right now.

Power Savings

With all this talk about higher performance we can’t forget that AMD has gone to great lengths to reduce power when not needed as well. Within Windows Vista and Windows 7 is a Ultra-low power state feature. This specific feature was created for multi-GPU video cards and configurations, and the Radeon HD 5970 (and HD 5800 series in general) supports it. This allows an Ultra-low power state which will put one of the GPUs on the video card to sleep when sitting in Windows Aero. This greatly reduces the idle power of the video card, where before both GPUs would be operating at their reduced "2D" speeds. This brings the total idle Wattage of the video card to an acceptable 42W for a dual-GPU package. With more than one display connected, we do understand the idle power rises, likely in the 70 watt neighborhood. We are working on getting a solid answer on that.

ATI Radeon HD 5970

The ATI Radeon HD 5970 is quite long. It measures in at a full 12.5 inches / 32 centimeters from the bracket to the outer edge of the red vent on the end. Small cases beware indeed. You will notice there are two DVI connections, and because AMD had to make the exhaust vent bigger on the bracket they were not able to use a full sized DisplayPort and HDMI connector. So instead, they opted to put a mini-DisplayPort connection on this video card.

AMD has also put exhaust vents along the top of the video, so heat is dissipated into your case, but it gives the video card much more breathing room. You will notice there is a CrossFire bridge included on this video card; that is because Radeon HD 5970 CrossFireX (Quad-GPU) is fully supported and enabled (but not in Eyefinity yet). You will need one 6-pin PCIe power connector and one 8-pin PCIe power connector for operation.